U.S. patent application number 13/653752 was filed with the patent office on 2013-11-21 for organic light-emitting display apparatus and method of manufacturing the same.
The applicant listed for this patent is Kyu-Sik CHO, Yul-Kyu LEE, Sun PARK, Ji-Hoon SONG. Invention is credited to Kyu-Sik CHO, Yul-Kyu LEE, Sun PARK, Ji-Hoon SONG.
Application Number | 20130306939 13/653752 |
Document ID | / |
Family ID | 49580574 |
Filed Date | 2013-11-21 |
United States Patent
Application |
20130306939 |
Kind Code |
A1 |
PARK; Sun ; et al. |
November 21, 2013 |
ORGANIC LIGHT-EMITTING DISPLAY APPARATUS AND METHOD OF
MANUFACTURING THE SAME
Abstract
An organic light-emitting display apparatus includes a thin film
transistor having an active layer, a gate electrode, and source and
drain electrodes, an organic light-emitting device having a pixel
electrode connected to the thin film transistor, an intermediate
layer including an emissive layer, and an opposite electrode, and
an opposite electrode contact portion having a joining region and
an insulating region. The opposite electrode and a power
interconnection line contact each other in the joining region. An
insulating layer is interposed between the opposite electrode and
the power interconnection line in the insulating region, and a
portion of the insulating layer penetrates into the power
interconnection line in the insulating region.
Inventors: |
PARK; Sun; (Yongin-City,
KR) ; LEE; Yul-Kyu; (Yongin-City, KR) ; CHO;
Kyu-Sik; (Yongin-City, KR) ; SONG; Ji-Hoon;
(Yongin-City, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
PARK; Sun
LEE; Yul-Kyu
CHO; Kyu-Sik
SONG; Ji-Hoon |
Yongin-City
Yongin-City
Yongin-City
Yongin-City |
|
KR
KR
KR
KR |
|
|
Family ID: |
49580574 |
Appl. No.: |
13/653752 |
Filed: |
October 17, 2012 |
Current U.S.
Class: |
257/40 ; 257/72;
257/E51.018; 438/34 |
Current CPC
Class: |
H01L 27/124 20130101;
H01L 27/1259 20130101; H01L 27/3276 20130101 |
Class at
Publication: |
257/40 ; 257/72;
438/34; 257/E51.018 |
International
Class: |
H01L 51/52 20060101
H01L051/52; H01L 51/56 20060101 H01L051/56 |
Foreign Application Data
Date |
Code |
Application Number |
May 18, 2012 |
KR |
10-2012-0053162 |
Claims
1. An organic light-emitting display apparatus, comprising: a thin
film transistor including an active layer, a gate electrode, and
source and drain electrodes; an organic light-emitting device
including a pixel electrode connected to the thin film transistor,
an intermediate layer having an emissive layer, and an opposite
electrode; and an opposite electrode contact portion including a
joining region and an insulating region, the opposite electrode and
a power interconnection line contacting each other in the joining
region, and an insulating layer being interposed between the
opposite electrode and the power interconnection line in the
insulating region, a portion of the insulating layer penetrating
into the power interconnection line in the insulating region.
2. The organic light-emitting display apparatus of claim 1, wherein
the power interconnection line includes: a first interconnection
layer that is formed on a same plane as the gate electrode, and a
second interconnection layer that is above the first
interconnection line, the second interconnection layer being formed
on a same plane as the source and drain electrodes.
3. The organic light-emitting display apparatus of claim 2, wherein
the power interconnection line includes a plurality of penetration
holes therein, the portion of the insulating layer being filled
into the plurality of penetration holes.
4. The organic light-emitting display apparatus of claim 3, wherein
the plurality of penetration holes penetrate from the second
interconnection layer to the first interconnection layer.
5. The organic light-emitting display apparatus of claim 4, further
comprising a pixel-defining layer for defining a pixel region of
the organic light-emitting device, the insulating layer being
formed on a same plane as the pixel-defining layer.
6. A method of manufacturing an organic light-emitting display
apparatus, the method comprising: forming a power interconnection
line in which a penetration hole is formed in an opposite electrode
contact portion on a substrate; forming an insulating layer above
the power interconnection line, a portion of the insulating layer
being filled into the penetration hole; and forming an opposite
electrode above the insulating layer, the opposite electrode
contacting the power interconnection line through a joining region
on the power interconnection line, the insulating layer being
excluded in the joining region.
7. The method of claim 6, further comprising forming an active
layer, a gate electrode, and source and drain electrodes of a thin
film transistor, wherein forming the power interconnection line
includes: forming a first interconnection layer on a same plane as
the gate electrode by using a same gate electrode forming material;
and forming a second interconnection layer on a same plane as the
source and drain electrodes by using a same source and drain
electrode forming material.
8. The method of claim 7, wherein the penetration hole includes a
plurality of penetration holes that are formed in the power
interconnection line.
9. The method of claim 8, wherein the plurality of penetration
holes are formed to penetrate from the second interconnection layer
to the first interconnection layer.
10. The method of claim 9, further comprising forming a
pixel-defining layer for defining a pixel region of the organic
light-emitting apparatus, the insulating layer being formed on a
same plane as the pixel-defining layer.
Description
CROSS-REFERENCE TO RELATED PATENT APPLICATION
[0001] This application claims priority under 35 U.S.C. .sctn.119
to Korean Patent Application No. 10-2012-0053162, filed on May 18,
2012, in the Korean Intellectual Property Office, the disclosure of
which is incorporated herein in its entirety by reference.
BACKGROUND
[0002] An organic light-emitting display apparatus may include a
thin film transistor and an organic light-emitting device. When an
appropriate driving signal is transmitted from the thin film
transistor to the organic light-emitting device, the organic
light-emitting device emits light to thus embody a desired
image.
SUMMARY
[0003] Embodiments may be realized by providing an organic
light-emitting display apparatus that includes: a thin film
transistor including an active layer, a gate electrode, and source
and drain electrodes; an organic light-emitting device including a
pixel electrode connected to the thin film transistor, an
intermediate layer including an emissive layer, and an opposite
electrode; and an opposite electrode contact portion including a
joining region in which the opposite electrode and a power
interconnection line contact each other and an insulating region in
which an insulating layer is interposed between the opposite
electrode and the power interconnection line. In the insulating
region, a portion of the insulating layer penetrates into the power
interconnection line.
[0004] The power interconnection line may include a first
interconnection layer, which is formed on the same plane as the
gate electrode, and a second interconnection layer, which is formed
on the same plane as the source and drain electrodes above the
first interconnection line. A plurality of penetration holes may be
formed in the power interconnection line, and a portion of the
insulating layer may be filled into the plurality of penetration
holes.
[0005] The plurality of penetration holes may penetrate from the
second interconnection layer to the first interconnection layer.
The organic light-emitting display apparatus may further include a
pixel-defining layer for defining a pixel region of the organic
light-emitting device. The insulating layer may be formed on the
same plane as the pixel-defining layer.
[0006] Embodiments may also be realized by providing a method of
manufacturing an organic light-emitting display apparatus that
includes: forming a power interconnection line in which a
penetration hole is formed in an opposite electrode contact portion
on a substrate; forming an insulating layer, of which a portion is
filled into the penetration hole, above the power interconnection
line; and forming an opposite electrode above the insulating layer
to contact the power interconnection line through a joining region
on the power interconnection line, in which the insulating layer
does not exist.
[0007] The method may further include forming an active layer, a
gate electrode, and source and drain electrodes of a thin film
transistor. The forming of the power interconnection line may
include forming a first interconnection layer on the same plane as
the gate electrode by using the same material, and forming a second
interconnection layer on the same plane as the source and drain
electrodes by using the same material.
[0008] A plurality of penetration holes may be formed in the power
interconnection line. The plurality of penetration holes may be
formed to penetrate from the second interconnection layer to the
first interconnection layer. The method may further include forming
a pixel-defining layer for defining a pixel region of the organic
light-emitting apparatus, wherein the insulating layer is formed on
the same plane as the pixel-defining layer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Features will become apparent by describing in detail
exemplary embodiments thereof with reference to the attached
drawings in which:
[0010] FIG. 1 is a cross-sectional view of an organic
light-emitting display apparatus according to an exemplary
embodiment;
[0011] FIGS. 2A to 2F are cross-sectional views depicting stages in
a method of manufacturing the organic light-emitting display
apparatus of FIG. 1, according to an exemplary embodiment; and
[0012] FIG. 3 is a plan view schematically illustrating a structure
of penetration hole arrangement of an opposite electrode contact
portion in the organic light-emitting display apparatus of FIG.
1.
DETAILED DESCRIPTION
[0013] Example embodiments will now be described more fully
hereinafter with reference to the accompanying drawings; however,
they may be embodied in different forms and should not be construed
as limited to the embodiments set forth herein. Rather, these
embodiments are provided so that this disclosure will be thorough
and complete, and will fully convey exemplary implementations to
those skilled in the art.
[0014] Expressions such as "at least one of," when preceding a list
of elements, modify the entire list of elements and do not modify
the individual elements of the list.
[0015] Like reference numerals in the drawings refer to like
elements. In describing the exemplary embodiments below, if it is
rendered that a detailed description about known associated
function or structure may make the subject matter unclear, the
detailed description will be omitted.
[0016] In the drawings illustrating exemplary embodiments, the
thickness or size of each layer illustrated in the drawings may be
exaggerated for convenience of explanation and clarity. Also, in
the present specification, when a constituent element such as a
layer, a film, a region, a plate, etc. is located "on" another
constituent element, the constituent element should be construed to
be located not only "directly on" the other constituent element,
but also above the other constituent element through at least one
of other constituent elements.
[0017] FIG. 1 is a cross-sectional view of a back-emission type
organic light-emitting display apparatus according to an exemplary
embodiment.
[0018] Referring to FIG. 1, the organic light-emitting display
apparatus according to the present embodiment includes a thin film
transistor TFT, an organic light-emitting device EL, and an
opposite electrode contact portion CNT. In the opposite electrode
contact portion CNT, an opposite electrode 35 of the organic
light-emitting device EL is connected to a power interconnection
line 40.
[0019] The thin film transistor TFT includes an active layer 21, a
gate electrode 20, and source and drain electrodes 27 and 29. The
gate electrode 20 may include a lower gate electrode 23 and an
upper gate electrode 25. The lower gate electrode 23 is formed of a
transparent conductive material, and the upper gate electrode 25 is
formed of a metallic material. A gate insulating layer 15 is
interposed between the gate electrode 20 and the active layer 21 to
insulate the gate electrode 20 from the active layer 21. Also,
source and drain regions into which high-concentration impurities
are injected are formed on opposing edge portions of the active
layer 21, and the source and drain electrodes 27 and 29 are
connected to the source and drain regions, respectively.
[0020] The organic light-emitting device EL includes a pixel
electrode 31 connected to one of the source and drain electrodes 27
and 29 of the thin film transistor TFT, the opposite electrode 35
functioning as a cathode, and an intermediate layer 33 interposed
between the pixel electrode 31 and the opposite electrode 35. In
FIG. 1, a reference numeral 50 denotes an interlayer insulating
layer (hereinafter referred to as a first insulating layer), and a
reference numeral 55 denotes a pixel-defining layer (hereinafter
referred to as a second insulating layer) for defining a pixel
region.
[0021] The power interconnection line 40 contacting the opposite
electrode 35 is disposed in the opposite electrode contact portion
CNT. The power interconnection line 40 includes a first
interconnection layer 41 and a second interconnection layer 42. The
first interconnection layer 41 and the gate electrode 20 are formed
of the same material on the same plane, and the second
interconnection layer 42 and the source and drain electrodes 27 and
29 are formed of the same material on the same plane. A region in
which the opposite electrode 35 directly contacts the power
interconnection line 40 is a contact region CNT2, e.g., in the
contact region CNT2 the second insulating layer 55 may be excluded
therein by way of a through hole therein. A region in which the
second insulating layer 55 is interposed between the opposite
electrode 35 and the power interconnection line 40 is an insulating
region CNT1. The insulating region CNT1 may be formed so as to
enclose the contact region CNT2.
[0022] A penetration hole 40a that penetrates to a depth of a
portion of the first interconnection layer 41 through the second
interconnection layer 42 may be formed in the power interconnection
line 40. The penetration hole 40a may expose the first
interconnection layer 41, e.g., the penetration hole 40a may expose
a layer formed of the transparent conductive material. The
insulating region CNT1 may be formed as the second insulating layer
55 is filled into the penetration hole 40a.
[0023] That is, the second insulating layer 55 of the insulating
region CNT1 electrically isolates the opposite electrode 35 from
the power interconnection line 40. In the present embodiment, a
joining area is increased by filling a portion of the second
insulating layer 55 into the penetration hole 40a, thereby
increasing binding strength. Accordingly, since binding strength
between the second insulating layer 55 and the power
interconnection line 40 is considerably increased, film-separation
may be suppressed.
[0024] In other words, in the insulating region CNT1, the first
insulating layer 50 is interposed between ends of the first and
second interconnection layers 41 and 42 as illustrated in FIG. 1,
and thus, a step is formed. In this case, stress may easily
concentrate on the step, and the concentrated stress may easily
cause film-separation in which, e.g., a gap is formed between the
second insulating layer 55 and the second interconnection layer 42.
However, when the second insulating layer 55 is filled into the
penetration hole 40a of the power interconnection line 40, as shown
in FIG. 1, a joining area is increased, and thus, binding strength
between the second insulating layer 55 and the power
interconnection line 40 is increased. Consequentially,
film-separation may be suppressed although stress concentrates on
the step.
[0025] Accordingly, as film-separation is suppressed, a power
connection state of the opposite electrode contact portion CNT may
be improved to be very stable.
[0026] Hereinafter, a method of manufacturing an organic
light-emitting display apparatus having a structure as described
above is described below with reference to associated drawings.
[0027] FIGS. 2A to 2F are cross-sectional views depicting stages in
a method of manufacturing the organic light-emitting display
apparatus of FIG. 1, according to an exemplary embodiment.
[0028] First, referring to FIG. 2A, a buffer layer 11, e.g., for
flatting the substrate 10 and preventing permeation of impurity
elements, is formed on the substrate 10.
[0029] The substrate 10 may be formed of a transparent glass
material that mainly consists of SiO.sub.2. However, the substrate
10 is not limited thereto, and various other substrates formed of,
for example, a transparent plastic material or a metallic material,
may also be used as the substrate 10.
[0030] The active layer 21 of the thin film transistor TFT is
formed on the buffer layer 11. The active layer 21 may be formed of
a polycrystalline silicon material by patterning using a mask
process. Thereafter, the gate insulating layer 15 is formed on the
patterned active layer 21. The gate insulating layer 15 may be
formed by depositing an inorganic insulating film, such as
SiN.sub.X or SiO.sub.x, by using, e.g., a chemical vapor deposition
process. For example, the chemical vapor deposition process may
include plasma-enhanced chemical vapor deposition (PECVD),
atmospheric pressure chemical vapor deposition (APCVD), or lower
pressure chemical vapor deposition (LPCVD).
[0031] Subsequently, as illustrated in FIG. 2B, a first conductive
layer 17 and a second conductive layer 19 are sequentially
deposited on the gate insulating layer 15. Then, the pixel
electrode 31 of the organic light-emitting device EL, the gate
electrode 20 of the thin film transistor TFT, and the first
interconnection layer 41 that constitutes the power interconnection
line 40 of the opposite electrode contact portion CNT, are formed
by patterning the first and second conductive layers 17 and 19.
[0032] The first conductive layer 17 may include at least one
material selected from ITO, IZO, ZnO, and In.sub.2O.sub.3, which
may be transparent materials. The second conductive layer 19 may
include at least one material selected from Ag, Mg, Al, Pt, Pd, Au,
Ni, Nd, Ir, Cr, Li, Ca, Mo, Ti, W, MoW, and Al/Cu.
[0033] The first conductive layer 17 and the second conductive
layer 19 are sequentially deposited on the whole surface of the
substrate 10, and then patterned by using a mask process to form
the gate electrode 20, the pixel electrode 31, and the first
interconnection layer 41.
[0034] The gate electrode 20 corresponds to the center of the
active layer 21, and in this form, by using the gate electrode 20
as a mask, the active layer 21 is doped with n-type or p-type
impurities, so that a channel portion is formed in a portion of the
active layer 21 covered by the gate electrode 20 and source and
drain portions are formed in a portion of the active layer exposed
by the gate electrode 20.
[0035] Referring to FIG. 2C, the first insulating layer 50 is
deposited on the whole surface of the substrate 10, and openings
H1, H2, H3, and H4 are formed therein by using a mask process.
[0036] The first insulating layer 50 may be formed by spin coating
at least one organic insulating material selected from a polyimide,
a polyamide, an acryl resin, a benzocyclobutene, and a phenol
resin, and may be formed in a thickness greater than that of the
gate insulating layer 15 to function as an interlayer insulating
layer between the gate electrode 20 and the source and drain
electrodes 27 and 29 of the thin film transistor TFT. Also, the
first insulating layer 50 may be formed of, in addition to those
organic insulating materials, the inorganic insulating materials
which have been described with reference to the gate insulating
layer 15. Alternatively, an organic insulating material and an
inorganic insulating material may be alternately used to form the
first insulating layer 50.
[0037] The first insulating layer 50 is patterned to form openings
H1, H2, H3, and H4, in which each exposes one of the pixel
electrode 31, the source and drain portions of the active layer 21,
and the first interconnection layer 41.
[0038] Referring to FIG. 2D, a third conductive layer (not shown)
is deposited on the resultant structure and then patterned to form
the source and drain electrodes 27 and 29 of the thin film
transistor TFT and the second interconnection layer 42 of the power
interconnection line 40.
[0039] The third conductive layer may be formed of a material
selected from the conductive materials described with reference to
the first or second conductive layers 17 and 19, or may be formed
of an Mo/Al/Mo material. The third conductive layer is patterned to
form the source and drain electrodes 27 and 29 and the second
interconnection layer 42. The pixel electrode 31 is etched to
partially expose the first conductive layer 17, and a penetration
hole 40a that penetrates the first and second interconnection
layers 41 and 42 is formed in the power interconnection line 40.
Also, although not illustrated in the drawings, one of the source
and drain electrodes 27 and 29 may be connected to the pixel
electrode 31.
[0040] Referring to FIG. 2E, the second insulating layer 55 is
formed on the substrate 10. The second insulating layer 55 may be
formed by, for example, spin coating at least one organic
insulating material selected from a polyimide, a polyamide, an
acryl resin, a benzocyclobutene, and a phenol resin. The second
insulating layer 55 is filled into the penetration hole 40a. In
this form, the second insulating layer 55 is patterned to form
openings H5 and H6 respectively exposing a central portion of the
pixel electrode 31 and a portion of the second interconnection
layer 42.
[0041] Thereafter, as illustrated in FIG. 2F, the intermediate
layer 33 including an organic emissive layer is formed inside the
opening H5 exposing the pixel electrode 31. Then, the opposite
electrode 35 is formed.
[0042] The intermediate layer 33 may include an organic emissive
layer (EML), and at least one layer selected from a hole transport
layer (HTL), a hole injection layer (HIL), an electron transport
layer (ETL), and an electron injection layer (EIL), each of which
may have a single- or multi-layered structure.
[0043] The opposite electrode 35 is deposited on the whole surface
of the substrate 10, and in this case, the opposite electrode 35
contacts the second interconnection layer 42 of the power
interconnection line 40 through the opening H6.
[0044] By performing these processes described above, a structure
in which the second insulating layer 55 of the opposite electrode
contact portion CNT is filled into the penetration hole 40a may be
formed, and thus, film-separation, that is, separation of the
second insulating layer 55 or the opposite electrode 35 deposited
on the power interconnection line 40 may be prevented.
[0045] A plurality of penetration holes 40a may be formed in the
power interconnection lines 40 as schematically illustrated in the
plan view of FIG. 3. Increasing the number of penetration holes 40a
so that a contact area contacting the second insulation layer 55 is
increased, may realize an improved effect of suppressing the
film-separation stated above.
[0046] As described above, according to organic light-emitting
display apparatuses and methods of manufacturing the same according
to exemplary embodiments, the possibility of film-separation, which
may occur in an opposite electrode contact portion, may be reduced
and/or prevented. Accordingly, a stable power connection to an
opposite electrode may be obtained. Further, due to the increased
area of a contact portion, resistance may be reduced and a voltage
drop may be reduced and/or prevented.
[0047] By way of summation and review, an organic light-emitting
display apparatus may include a thin film transistor and an organic
light-emitting device. The thin film transistor may include an
active layer, a gate electrode, and source and drain electrodes,
which all are stacked on a substrate. Accordingly, when a current
is supplied to the gate electrode via an interconnection line
formed on the substrate, a current flows in the source and drain
electrodes via the active layer. Further, a current flows in a
pixel electrode of the organic light-emitting device connected to
the source and drain electrodes.
[0048] The organic light-emitting device of the organic
light-emitting display apparatus may include the pixel electrode,
an opposite electrode facing the pixel electrode, and an emissive
layer interposed between the pixel electrode and the opposite
electrode. When the current flows in the pixel electrode via the
thin film transistor, an appropriate voltage level is formed
between the opposite electrode and the pixel electrode, and thus,
the emissive layer emits light to embody an image.
[0049] To form the appropriate level of voltage in the emissive
layer, the opposite electrode may retain an appropriate voltage
level by connection with a power interconnection line. However,
film-separation may occur at a contact portion of the opposite
electrode and the power interconnection line.
[0050] For example, the power interconnection line connected to the
opposite electrode may include a plurality of interconnection
layers, and an insulating layer may be interposed between ends of
the interconnection layers. In this structure, the end of the power
interconnection line with the insulating layer interposed between
the interconnection layers protrudes more than a central portion of
the power interconnection line, thereby forming a step.
Accordingly, another insulating layer covering the ends of the
power interconnection line and the opposite electrode, which is
formed on the insulating layer to contact the power interconnection
line, do not completely contact the power interconnection line due
to the step, and thus, a gap may be formed therebetween resulting
in film-separation. Once film-separation occurs, power connection
to the opposite electrode may be unstable, thereby causing defects
in products due to the generation of heat.
[0051] In contrast, embodiments relate to an organic light-emitting
display apparatus and to an organic light-emitting display
apparatus in which the structure of an opposite electrode
contacting an interconnection line is improved. Further, the
improved structure, e.g., for suppressing film-separation at a
contact portion of an opposite electrode, may embody a stable
organic light-emitting display apparatus.
[0052] Embodiments also relate to an organic light-emitting display
apparatus that is improved to suppress an occurrence of
film-separation at an opposite electrode contact portion, and a
method of manufacturing the organic light-emitting display
apparatus. Embodiments further relate to an organic light-emitting
display apparatus in which a structure may increase a binding
strength of the insulating layer, and thus, film-separation may be
suppressed. Embodiments also relate to an organic light-emitting
display apparatus in which film-separation at an opposite electrode
contact portion may be suppressed, and thus, stable power
connection to an opposite electrode may be secured, thereby
reducing defects in products.
[0053] Exemplary embodiments have been disclosed herein, and
although specific terms are employed, they are used and are to be
interpreted in a generic and descriptive sense only and not for
purpose of limitation. Accordingly, it will be understood by those
of ordinary skill in the art that various changes in form and
details may be made without departing from the spirit and scope of
the present invention as set forth in the following claims.
* * * * *